While the value of fielding isn't entirely
unmeasurable, as Branch Rickey surmised, fielding
statistics are more fraught with biases than others. The
traditional measure of defensive prowess, fielding
percentage, benefits a sure-handed player with limited
range. A shortstop who never exerts himself to make a
play on balls hit beyond his immediate area might compile
a high fielding percentage, but many base hits he made no
attempt to prevent will find their way through the
infield. Fielding percentage is calculated as (assists
plus putouts) divided by (assists plus errors plus
putouts).

A superior tool for evaluating fielders, other than
first basemen and catchers, is range factor. Range factor
is simply the number of successful chances a fielder
makes per game, calculated as (assists plus putouts)
divided by games. Like fielding percentage, range factor
has its flaws.

A player on a team laden with strikeout pitchers will
have fewer opportunities to make plays in the field. The
left/right-handedness of pitchers will affect a player's
range factor, as will the pitching staff's
groundball/flyball tendencies. Ballparks have an
influence, too, especially the amount of outfield space
and foul territory available to fielders. While park
factor data exists to adjust batting and pitching
statistics, it is unfortunately almost unheard of for
fielding statistics. In addition, range factor is best
calculated using innings played instead of games, but
innings played aren't easily available.

For lack of a better measure, though, range factor is
still fairly useful to evaluate second and third basemen,
shortstops, and outfielders.

In addition to range factor, assists are also used to
evaluate the arms of outfielders. The adage is that
because baserunners are afraid to challenge them,
outfielders with good arms don't get many assists. While
this point may be debated, an outfielder with many
assists has still succeeded in throwing out a lot of
runners, a fact that should not be overlooked. Assists
are presented per 162 games, calculated as (assists times
162) divided by games.

Range factor is not a good measure for first basemen,
since most of their fielding chances are putouts made
simply by receiving throws to first base. Skills
important to a first baseman include starting double
plays, fielding bunts, making unassisted plays, and
handling difficult throws. These abilities are
essentially unidentifiable by traditional fielding
statistics. In any event, first base is the least
demanding defensive position, and it would be highly
unusual for a team to retain a first baseman chiefly for
his defensive value.

Catchers are also ill-served by range factor,
particularly because many of their putouts are
accumulated on strikeouts. A catcher acquires his
defensive reputation mainly by his ability to throw out
baserunners, block pitches in the dirt, and handle a
pitching staff. A catcher's capacity to halt the running
game is affected by how well his pitchers hold runners.
Similarly, while a catcher's earned-run average gives an
idea of his competence in handling pitchers, the pitchers
themselves have an influence on this statistic, too.
Baserunning statistics and earned-run averages for
catchers are available from ESPN's
player profiles.

First basemen and catchers are evaluated here by
fielding percentage, which, while inadequate, says
something about the player's ability to handle chances
safely. Moreover, assists are used to gauge first basemen
and catchers for their ability to reach balls hit into
their area as well as to throw out runners. While still
an imperfect measure, assists give some idea of fielding
skill beyond the misleading influence of putouts for
first basemen and catchers. As with outfielders, assists
are presented per 162 games.

More accurate and sophisticated means of evaluating
fielders have been and are being devised. To see some
other methods, check out the zone ratings compiled by
STATS, Inc., found in the player profiles on CNN/SI
and ESPN.
Zone ratings attempt to evaluate fielders based on what
percentage of plays they make in their defensive area, or
zone. STATS features some other innovative defensive
statistics in its annual Baseball
Scoreboard. Pete Palmer's fielding runs
formula is described in the Total
Baseball glossary, and career fielding runs and
fielding wins for all major-leaguers are listed in the
player records in Total
Baseball. Researcher Charlie Saegar wrote
an article, "Ready
for the Defense," on his approach to fielding
statistics, which can be found in the latest edition of
the Big Bad
Baseball Annual.